title: Quantitation of the octadecanoid 12-oxo-phytodienoic acid, a signalling compound in plant mechanotransduction.
abstract: The octadecanoid 12-oxo-phytodienoic acid (OPDA) is an intermediate in biosynthesis of jasmonic acid in plants. A technique for the quantitation of this compound is described which has a limit of detection of 20 pg cis-OPDA corresponding to 4 ng g-1 tissue for the overall procedure and which uses high isotopic abundance [2H5]cis-(+/-)-OPDA, synthesized enzymatically by recombinant allene oxide synthase, as internal standard. The levels of cis-OPDA have been determined in a wide variety of monocotyledonous and dicotyledonous angiosperms and were found to vary considerably among different species. In mechanically stimulated tendrils of Bryonia dioica, the level of cis-OPDA increases several-fold, correlating with the initiation and progression of the free coiling response. In Phaseolus vulgaris internodes undergoing a thigmomorphogenic response, the levels of cis-OPDA were also found to increase several-fold well before the development of thigmomorphogenic symptoms. The thigmomorphogenic reaction could also be triggered by application of the octadecanoid structural analog, coronatine. Coronatine did not induce OPDA accumulation in treated tissues and is thus active per se. In both species, Bryonia dioica and Phaseolus vulgaris, the (+)-enantiomer of cis-OPDA is found and accumulates after mechanical stimulation. Our results establish 12-oxo-phytodienoic acid as a signalling compound in higher plant mechanotransduction.
authors.affiliation: Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität, Bochum, Germany.
authors.forename: B A
authors.initials: BA
authors.lastname: Stelmach
authors.forename: A
authors.initials: A
authors.lastname: Müller
authors.forename: P
authors.initials: P
authors.lastname: Hennig
authors.forename: D
authors.initials: D
authors.lastname: Laudert
authors.forename: L
authors.initials: L
authors.lastname: Andert
authors.forename: E W
authors.initials: EW
authors.lastname: Weiler
mesh_terms: D003903:Deuterium; D007887:Fabaceae / Q000737:chemistry / Q000502:physiology*; D005231:Fatty Acids, Unsaturated / Q000032:analysis / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D019684:Magnoliopsida / Q000737:chemistry / Q000502:physiology*; D009024:Morphogenesis; D010812:Physical Stimulation; D010946:Plants, Medicinal; D012680:Sensitivity and Specificity; D015398:Signal Transduction; D013045:Species Specificity
chemical_list: D005231:Fatty Acids, Unsaturated; C025999:12-oxophytodienoic acid; D003903:Deuterium